The Verge confirms an earlier story by Mary Jo Foley. "Microsoft is preparing to revive the traditional Start button it killed with Windows 8. Sources familiar with Microsoft's plans have revealed to The Verge that Windows 8.1 will include the return of the Start button. We understand that the button will act as a method to simply access the Start Screen, and will not include the traditional Start Menu. The button is said to look near-identical to the existing Windows flag used in the Charm bar."

So far the word is that the Windows Runtime includes support for more peripherals. Deeper USB, Bluetooth, Kiosk, and Point of Sale APIs are baked into the platform now.

As for WP8.1 and Windows 8.1 parity, I think we'll see more movement in the general direction but nothing completely earth shattering. More APIs will be in sync, but I don't imagine them moving off of the Silverlight stack in Windows Phone until at least WP9.